Product containers such as bottles, are labeled by various methods. Early methods involved either printing information directly onto the container or alternatively printing the information on a paper label that was then adhesively bonded to the container. More recently, paper labels have often been supplanted by plastic labels because they are inexpensive and provide an attractive appearance. While adhesively-secured labels inhibit recycling, they continue to be used because of the speed with which bottles can be labeled. With the introduction of the machine of the Delabler Patent, tubular plastic sleeves have become an economical alternative to wrap around adhesively bonded labels.
When an adhesive-connected plastic label is used on a plastic bottle, the portion of the bottle contacting the adhesive is not economically recoverable with known recycling processes because the label and bottle plastics are different, typically polyethylene for labels and P.E.T. for the bottles, and the label cannot be separated from the bottle. Moreover, such bottles normally are not reusable for the same reason. When non-adhesive sleeves are used, the sleeves can be separated from the bottles thereby making all or substantially all of each bottle and label recyclable and allowing for the reuse of the bottle in the alternative. Thus, sleeved bottles comply with laws mandating fully recyclable bottles.
While tests have shown the machine of the Delabeler Patent to be quite satisfactory for some applications, currently there are no satisfactory methods or apparatus for facilitating bottle reuse by economically and concurrently removing plastic labels from each bottle of a set of bottles. Consequently, in many applications, paper labels, rather than less expensive and more attractive plastic labels, continue to be used on reusable bottles.
In desleeving operations, the effort to remove the sleeve from the bottle is resisted by the frictional forces between the sleeve and bottle. Sleeves for bottles are initially smaller in diameter than the bottle being sleeved. Thus, each sleeve is stretched as it is placed on the bottle. In addition to the friction induced by stretching the labels, other factors can exacerbate the frictional resistance to removing a sleeve over a bottle. For example, some types of plastic used for bottles such as polyethylene, have a low-friction surface, but others such as PET material, have a very high-friction surface. Some labels have printing on their inside surfaces. Such printing increases the friction between the sleeve and the bottle. Additionally, it has recently been learned that there is a problem with non-adhesive sleeves in that when a sleeve becomes wet, after the sleeve has dried, it will be "adhered" to the bottle even though it is nonadhesive. This "adherence" makes it difficult to remove the sleeve.
Accordingly, there is a need for a reliable, low cost method and apparatus for removing tubular sleeves from set of fluid vessels to allow economic reuse.